Storage of fiber-guided light in a nanofiber-trapped ensemble of cold atoms

TL;DR

This paper demonstrates the storage and retrieval of fiber-guided light in a cold atom ensemble trapped around a nanofiber, showing potential for quantum information networks.

Contribution

It introduces a method to store optical pulses at the single-photon level in a nanofiber-trapped cold atom ensemble with measurable efficiency.

Findings

Achieved slow light with group velocity of 50 m/s.

Stored and retrieved optical pulses with 3.0% efficiency.

Demonstrated potential for quantum information applications.

Abstract

Tapered optical fibers with a nanofiber waist are versatile tools for interfacing light and matter. In this context, laser-cooled atoms trapped in the evanescent field surrounding the optical nanofiber are of particular interest: They exhibit both long ground-state coherence times and efficient coupling to fiber-guided fields. Here, we demonstrate electromagnetically induced transparency, slow light, and the storage of fiber-guided optical pulses in an ensemble of cold atoms trapped in a nanofiber-based optical lattice. We measure a slow-down of light pulses to group velocities of 50 m/s. Moreover, we store optical pulses at the single photon level and retrieve them on demand in the fiber after 2 microseconds with an overall efficiency of (3.0 +/- 0.4) %. Our results show that nanofiber-based interfaces for cold atoms have great potential for the realization of building blocks for future optical quantum information networks.